Actuators, motors, sensors and other electromechanical devices and transducers use magnetic components or components subjected to a magnetic field to convert electrical energy into mechanical motion or mechanical motion into electrical energy. Often the performance of such devices is dependent upon the capacity of a component, hereinafter referred to as a magnetic component, to conduct magnetic flux and the energy losses incurred in exciting the magnetic component to a given flux value at a certain rate. Measurement equipment and methods are known for measuring the capacity of a magnetic component to conduct magnetic flux. Similarly, measuring equipment and gauges are known for measuring the energy losses incurred in exciting a magnetic component to a given flux value. Measurement of the performance of such components is valuable as a quality control measure at the time of manufacturing such components and for subsequent diagnostic testing.
The disclosed device includes a flux path closure device for electrically coupling to a magnetic component to form a closed magnetic flux path and a coil for inducing a magnetic flux in the magnetic component through the closed magnetic flux path. The flux path closure device may be formed of a material that reduces energy losses to the flux path closure device by suppressing eddy currents within the flux path closure device. To suppress eddy currents within the flux path closure device, the flux path closure device may be fabricated from laminates. Alternatively, the flux path closure device may be fabricated from insulated powder in order to suppress eddy currents. Oxide-coated pressed metal particles may also be used to fabricate path closure device. Spacers may be disposed between flux path closure device and magnetic component. An appropriate spacer may be fabricated from non-magnetic material. An appropriate spacer may be fabricated from non-conductive material. Appropriate materials from which spacers may be fabricated include paper, glass, ceramics and other non-magnetic and non-conductive materials.
In the disclosed device, an excitation coil is attached to flux path closure device. Excitation leads electrically coupled to the excitation coil and a signal source provide an excitation signal to the excitation coil. The signal source generates a transient signal so that excitation coil generates a transient magnetic flux. The signal source may generate a transient current signal of a specified shape that is applied to the coil to generate a transient magnetic flux through the magnetic component and the flux path closure device. The signal source may alternatively generate a transient voltage signal of a specified shape that is applied across the terminals of the excitation coil to generate a transient magnetic flux through the magnetic component and the flux path closure device. A monitoring device is coupled to the excitation coil to monitor voltage across the coil terminals and current through the excitation coil. The monitoring device is configured to calculate an effective resistance of the excitation coil from voltage and current data inputs and to calculate the flux using voltage and current data and the calculated effective resistance. The monitoring device may include a graph generating device for generating flux vs. time graphs, current vs. time graphs, voltage vs. time graphs, flux linkage vs. time graphs and/or flux linkage vs. current graphs.
The disclosed method of evaluating the magnetic performance of a magnetic component includes coupling a flux path closure device to the magnetic component to form a closed magnetic flux path through the flux path closure device and the magnetic component, energizing an excitation coil by forming a voltage potential difference across terminals of the coil and passing current through the coil to generate a magnetic flux in the closed magnetic flux path, obtaining voltage data indicating the voltage potential across the terminals of the coil and current data indicating the current through the coil, calculating an effective resistance of the coil using the voltage data and the current data, calculating the flux using the calculated effective resistance and using the calculated flux to determine the flux capacity of and energy losses experience by the magnetic component. The method may include the step of graphing the flux over time. The energizing step may be accomplished by generating a transient current signal through the coil. The energizing step may be accomplished by generating a transient voltage signal applied across terminals of the coil.
These and other objects of the present invention will become more apparent from the following description of the illustrative embodiments.